Coordination polymers (CPs) better known as metal-organic frameworks (MOFs) have attracted considerable attention in the last decade as an important class of organic-inorganic hybrid materials able to absorb and release active pharmaceutical ingredients (APIs). Several MOFs have been demonstrated to absorb therapeutic molecules with unprecedented high loading capacities (i.e. MIL-100 and MIL-101), and their ability for controlled-release has been also explored. Yet, the biocompatibility of the polyfunctional organic molecules and/or metal cations (Ba2+, Sr2+, Cr2+, Cu2+, Cd2+, and Co2+) used to construct the existing extended arrays remains largely a concern, hindering their success in biomedical applications. Recently, the use of biologically relevant or bioactive metal cations has been investigated to introduce additional properties such as imaging and antibacterial activity. The application of MOFs for drug delivery can be accomplished by (1) the entrapment of API within the pores and/or (2) the incorporation of the API as a constituent of the framework. However, the biomedical applications for MOFs, including those in the nanometer size, remain a largely unexplored research arena.